Hi Shawn,
Am Donnerstag, 5. Januar 2017, 17:31:21 schrieb Shawn Lin:
> We need to modify the drive impedance according to the
> different hardware condition. So let's expose this to
> the DT.
>
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> ---
>
> Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt index
> e3ea557..731aeb9 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> +++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> @@ -14,6 +14,11 @@ specified by name:
> access to it), it is strongly suggested.
> - clocks: Should have a phandle to the card clock exported by the SDHCI
> driver.
>
> +Optional Properties:
> +- drive_impedance: Must be one of 33, 40, 50, 66, 100. This property allows
> + different boards to specify their own drive impedance depending on the
> + hardware condition.
In what unit are your 33, 40 etc values?
It is recommended that properties should specify their unit, see all the
properties ending in "-ma", "-ns" and so on and also
Documentation/devicetree/bindings/property-units.txt
Also properties should use dashes ("-") not underscores.
Judging by the second patch, these are Ohm, so combining the above you
probably want
drive-impedance-ohms
as property name.
Also the patch subject is slightly misleading and should probably specify the
rockchip-emmc as well :-)
Heiko
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
